Blecharczyk keeps Airbnb's infrastructure running smoothly on a global level--the company is in 191 of the 194 countries in the world. That global footprint makes for a host of possible snafus that Blecharczyk and his team have to handle, from making sure hosts get paid to ensuring safety of users and following government regulations.

Incredibly, Blecharczyk is not just one of the founders; he's also a client. Even though he is reportedly worth $3.3 billion, Blecharczyk still enjoys hosting Airbnb guests, though they rarely realize who their hardworking host is.

That's one of the things that makes Airbnb and other "sharing economy" businesses like Uber so popular and profitable: the ability to be your own boss.